[ 135 ] book review roundtable • asia ’ s regional architecture Path Dependence, Resilience, and the Gradual Transformation of Regional Architectures in Asia Kei Koga A ndrew Yeo’s new book, Asia’s Regional Architectures: Alliances and Institutions in the Pacifc Century, provides a comprehensive overview of Asia’s regional security architecture in the post–World War II period, exploring why Asia’s regional institutions have overlapped and coexisted for so long and how they have been shaped and are shaping regional actors’ ideas and behavior. Just as international relations scholars have begun looking at historical institutionalism to explain international issues, ones ranging from interstate relations to regional security institutions to nonproliferation regimes, Yeo employs its theoretical approach to analyze the establishment and evolution of regional architecture from the postwar period onward. He provides detailed yet succinct accounts of the main political, economic, and security regional institutions in Asia. 1 A plethora of insights are contained in this book, and among them three elements stand out. First, the book’s defnition of “regional architecture” allows readers to look at the big picture of regional institutions and governance in Asia. According to Yeo, regional architecture refers to “an overarching, comprehensive institutional structure within a geographic region that facilitates the coordination, governance, and resolution of a range of policy objectives of concern to states within that area” (p. 8). Tis broad defnition is important because it does not solely focus on “multilateralism” or “bilateral alliances” in Asia, which is a tendency in conventional studies on this subject. Rather, the defnition enables us to understand the dynamic interaction of two main regional institutional frameworks: the U.S. hub-and-spoke network and the multilateral institutions led by the Association of Southeast Asian Nations (ASEAN). Given that these institutions functionally overlap and contribute to maintaining regional 1 For other works employing historical institutionalism, see Orfeo Fioretos, Creative Reconstructions: Multilateralism and European Varieties of Capitalism afer 1950 (Ithaca: Cornell University Press, 2011); Kei Koga, Reinventing Regional Security Institutions in Asia and Africa: Power Shifs, Ideas, and Institutional Change (Oxford: Routledge, 2017); Wilfred Wan, Regional Pathways to Nuclear Nonproliferation (Athens: University of Georgia Press, 2018); and Orfeo Fioretos, ed., International Politics and Institutions in Time (Oxford: Oxford University Press, 2017). kei koga is an Assistant Professor at the Public Policy and Global Afairs Programme in the School of Social Sciences at Nanyang Technological University in Singapore. He can be reached at <kkei@ntu.edu.sg>.